95 transmission shudder under load

[vette eaterr]

I remember reading about someone having a similar problem and snipping a wire to "fix" it, but I can't find the thread and my Google powers aren't very good today.

When the van is cold the transmission shifts fine, once up to operating temp under load the trans shudders, then after a while shudders all of the time. To stop this I've been putting the trans in drive and that stops the shudder for a bit then it comes back, though not as rough as in over drive.

1995 3.8 4t60-e

Thanks,
Bob

[LMP]

..A possibility is the TCC clutch slipping under load....and you can test this by pulling out the A or D pin from the transmission connector.
As suggested by GM, "other" causes of shudder can be filtered out by keeping only the "fluid" coupling instead of the hard TCC coupling ..so maybe this just masks the effect, and not the cause...but anyway, I think is id worth trying for the sake of testing. ...and notice this will pop the check engine light ON, because it will detect permanent TCC slip as well as incorrect voltage reading on the TCC solenoid...

http://www.avigex.ca/xport/tccconnector.jpg

www.avigex.ca/xport/tccshudder.jpg

I have a problem of this sort on mine too....but I have finally found that while pulling TCC out will ease the perception, the problem stays, though much more subtle. My main suspect now is the fact that the right half drive shaft section entering the transmission has a bit of angular play, propbably the inner bushing slightly worn out...and it then wobbles somewhat radially under some load conditions. I can make it wobble by hand...and I do not like that. There is a very short transmission inner lenght for keeping this part aligned (the length of the bushing..that is the short flat section past the splines ) so a very small amount of lateral or diameter play translates into a noticeable angular wobbling.
www.avigex.ca/xport/rightshaftend.jpg
www.avigex.ca/xport/righttransmissionend.jpg
CHanging the inner bushing is next summer project...requires dropping the transmission a little down from its support and removing the end cap (so says the transmission shop)...the shop guy told me if it keeps the oil inside there is no need to change it...but I think I will not wait for that...
THe left side shaft is longer and has a much longer support length within the transmission so is much less subject to that problem and in my case, is totally free from any wobble at all.

[vette eaterr]

lol.....all of our vans have some sort of problem that we just learn to deal with...

That exactly what I was looking for. thanks LMP.

Bob

[PDESORM]

Hi guys,
Some great advise as usual. I have a 93, 3.8 and had the same problem: shudder at speed, often headed up hill on slight turns. The shudder went away after I put on new plugs and wires, and put in another (used) set of coils. Hasn't shuddered since!
Phil.

P.S. I am retireing my Trans Sport next week. The bottom frame is the problem, it's all rusted out. What do you expect afte 435,000 k!!!.

[96tsport]

Just ran across this gm axle stabilizer bearing & seal option; an axle seal with a needle bearing built in, but haven't found one for your tranny . Might try it out if you can find one that fits.

Here's one for dodge trannys that also explains it.

Originally Posted by LMP

I have a problem of this sort on mine too....but I have finally found that while pulling TCC out will ease the perception, the problem stays, though much more subtle. My main suspect now is the fact that the right half drive shaft section entering the transmission has a bit of angular play, propbably the inner bushing slightly worn out...and it then wobbles somewhat radially under some load conditions. I can make it wobble by hand...and I do not like that. There is a very short transmission inner lenght for keeping this part aligned (the length of the bushing..that is the short flat section past the splines ) so a very small amount of lateral or diameter play translates into a noticeable angular wobbling.
www.avigex.ca/xport/rightshaftend.jpg
www.avigex.ca/xport/righttransmissionend.jpg
CHanging the inner bushing is next summer project...requires dropping the transmission a little down from its support and removing the end cap (so says the transmission shop)...the shop guy told me if it keeps the oil inside there is no need to change it...but I think I will not wait for that...
THe left side shaft is longer and has a much longer support length within the transmission so is much less subject to that problem and in my case, is totally free from any wobble at all.

[robertv9809]

dumb as it sounds my transmission SHUDDER was actually caused by a weak coil pack

[yellowfiero]

Originally Posted by robertv9809

dumb as it sounds my transmission SHUDDER was actually caused by a weak coil pack

True.

My '95 had this problem, and it was a bad plug wire.